The physiological effect of fruit maturity and ۱-methylcyclopropene on ‘Hass’ avocado fruit exocarp colour and chilling injury during ripening

Purpose: This study was undertaken to investigate the influence of harvest maturity and ۱-methylcyclopropene (۱-MCP) treatment on exocarp colour development and chilling injury of ‘Hass’ avocado fruit during ripening. Research method: ‘Hass’ avocado fruit harvested at three different maturity stages, early (۲۱% DM), mid-(۲۸% DM) and late (۳۵% DM) were treated with ۳۰۰ g mol-۱ of ۱-MCP for ۱۶ hours and stored at ۵.۵ °C for ۲۸ days, subsequently, ripened at ۲۱ °C. The physico-chemicals quality parameters evaluated every ۲ days includes exocarp subjective (visual colour), objective (lightness-L*, chroma-C* and hue angle-ho), chlorophyll-a and -b, total anthocyanin, cyanidin ۳-O-glucoside and chilling injury. Findings: ۱-MCP delayed ripening for early and mid-matured fruit and extended ripening by ۲-۴ days when compared with untreated fruit. In this study, exocarp colour development of ‘Hass’ avocado fruit was improved by ۱-MCP treatment as measured visual and objectively. The accumulation of total anthocyanins and cyanidin ۳-O-glucosides in ۱-MCP-treated fruit was slower than that in untreated fruit, however, ۱-MCP treatment was associated with higher concentrations after fruit had reached ‘eat-ripe’ firmness, irrespective of maturity. The study found that ۱-MCP reduced the development of chilling injury symptoms for early harvested and mid-harvested ‘Hass’ avocado fruit. Research limitations: The main limitation of the present study is the lack of evaluation of ethylene production. Originality/Value: The study found that different maturity stages of ‘Hass’ avocado fruit responded differently to ۱-MCP treatment. Thus, ۱-MCP had a positive effect on early and mid-harvest fruit exocarp colour and CI development during ripening.

کلیدواژه ها:

anthocyanin ، Avocado colour ، chlorophyll ، Cyanidin ۳-O-glucoside ، Total carotenoids